In the prior art, an adjustment screw head is mounted on the headlight by means of a capsule including means for fixing it permanently to the body of the reflector and means for removably receiving the head of the screw. The fixing means conventionally used include gluing, welding, screwing, and the like.
A major drawback of these prior capsules lies in the fact that the above-mentioned fixing means are totally unsuitable for robot assembly of motor vehicle headlights, or the like.